500-750 extra calories per day would probably go a long way. Here are my general recommendations for healthy calorie dense additions. Even a few of these would add a quality amount of calories.

--A big handful or two (or three) of almonds per day.
--Some butter on your veggies. A little goes a long way and adds plenty of calories. Plus butter is packed with good nutrition.
--Whole milk instead of what you are drinking now...if you're not drinking whole milk.
--Add 2 dollops of sour cream to every possible meal.
--Add cheese to every possible meal.
--Rotate in plenty of beef each week.
--Add a little heavy cream to your shake.
--Buy fewer lean cuts of meat.
--Bacon strips. Bacon strips. Bacon strips. Seriously though, most grocery stores sell bacon bits and pieces in 3 to 5 pound bags, and these are great additions to many meals.
--Add a dollop or two of mascarpone to your shake. It hides well, is used in desserts, and packs a lot of calories.
--Natural sausage, skin and organ meat.

Wow how to get kcals would be my LEAST worry in MY diet- i can eat all day

+cue: some oil in the shake. One Tablespoon equals about 75kcals. You won´t taste it or it will taste EVEN BETTER. (remember fat is a taste transporter)